Warp end tying machine

ABSTRACT

Warp end tying machine for tying together the threads of two warp thread groups. There is provided a device for tying together the ends of two groups of warp threads which comprises essentially a tying hook, a cutting device, and a reciprocable suction tube having a jaw-shaped mouth. The tying hook comprises a radial projection on a rotatable tube, said tube being hollow and connected to a source of suction. The suction tube functions both as holding means for the threads to be tied and as disposal means for disposing of the cut ends thereof. The suction tube first receives the threads and holds same in a first position with respect to the tying hook, such that the hook in rotating about its axis will form the thread into a loop. After such rotation is completed, the suction tube holder moves parallel with the axis of the tying hook to bring a portion of the threads ahead of the loop made by rotation of the hook. A cutter then cuts said threads close to the hook and suction within the hook draws said end inwardly and through such loop. The knot may now be drawn tight and same is completed.

United States Patent 1191 Bar 2 v 11 1 3,813,742 [4 June 4, .1974

[5 1 WARP END TYING MACHINE [75 Inventor: Hans Bar, 8900 Augsburg,

Germany [73] Assignee: Knotex Maschinenbau Gnfl-I,

Augsburg, Germany [22] Filed: Aug. 17,1972

[21] Appl. No.: 281,490

Primary ExaminerLouis K. Rim rodt Attorney, Agent, or FirmWoodhams, Blanchard & Flynn [57] l I v ABSTRACT Warp end tying machine for tying together the threads of two warp thread groups. There is provided a device for tying together the ends of two groups of warp threads which comprises essentially a tying hook, a cutting device, and a reciprocable suction tube having a jaw-shaped mouth. The tying hook comprises a radial projection on a rotatable tube, said tube being hollow and connected to a source of suction. The suction tube functions both as holding means for the threads to be tied and as disposal means for disposing of the cut ends thereof. The suction tube first receives the threads and holds same in a first position with respect to the tying hook, such that the hook in rotating about its axis will form the thread into a loop. After suchrotation is completed, the suction tube holder moves parallel with the axis of the tying hook to bring a portion of the threads ahead of the loop made by rotation of the hook. -A cutter then cuts said threads close to the hook and suction within the hook draws said end inwardly and through such loop. The knot may now be drawn tight and same is completed.

6 Claims, 10 Drawing Figures PATENTEDJUH 4 19m sum 1 [1F 3 PATENTEDJM 4 974 SHEEI 2 OF 3 l WARPEND TYING MACHINE The invention relates to a warp end tying machine for tying the threads of two warp thread groupings, said 'machine comprising a tyinghook and a holding device for the two threads which are to be tied. Said holding device is arranged laterally alongside the tying hook and is movable relative to the tying hook preferably in the longitudinal direction of same.

The known warp end tying machines have besides the thereby moves the two threads over the tying hook behind its jaw. By now rotating the tying hook the threads are engaged by the jaw and are looped around the tying hook. Thereafter the clamp moves forwardly and brings the threads in front of the jaw of the tying hook so that they slide off from same and in this manner the knot is formed. A cutter arranged'between the tying hook and the thread clamp thereafter cuts oh the portion of the threads lying behind the knot. During the entire described process the thread clamp holds the two thread ends and moves the threads back and forth in axial direction of the tying hook. In then continuing the tying operation, the portions of the threads lying behind the knot are engaged by the tying needle and are pulled into the tying hook. In this manner, the threads are clamped between the insde surface of the tying hook and the needle and the knot can be tightened by the knot tensioner. The remaining portion of the threads which lie behind the knot is now cut off by a further cutter.

The thread clamp contains two clamping jaws pressed together by spring force. In order that the threads extend between the clamping jaws, grippers are provided which pull the threads against the spring force and the spring tension into the clamping jaws. By the friction on the clamping jaws and the grippers, however, the threads are considerably stressed. This limits the tying speed in the known tying machines since otherwise threads will be over-stressed and will break.

Therefore the basic purpose of the invention is to produce a warp end tying machine of the type mentioned-above which is simple in structure and permits higher tying speeds while simultaneously protecting the threads.

This is achieved according to the invention by constructing the holding device as a suction tube and connecting same to a suction source. For example, the blower of a vacuum cleaner can within the scope of the invention be used as a suction source. The new warp end tying machine is extremely simple in its structure, because the gripper and the clamp are not needed. The thread ends are held by means of suction force by the suction tube holding device. The suction tube performs the samemovements with respect to the tying hook as the above-described thread clamp. However, the rubbing movement between the clamping jaws of the thread clamp and the mechanical stress imposed by the grippers of the prior art are both eliminated. Also the latter are no longer required. Thus the threads are substantially less stressed and higher tying speeds are made possible. If the threads are cut off before the thread ends arepulled into the tying hook, the cut-off parts of the threads are immediately drawn off bythe suction tube and contamination of the machine is thereby avoided. v

' Further developments of the basic concept of the invention are embodied in the subclaims.

In known tying machines, after the loop formation of the tying hook, the thread ends are engaged by the tying needle. This tying needle is expensive to manufacture and can be used only for a small range of yarn thickness. Furthermore, the adjustment of the courses of movement of tying needle and tying hook is relatively difficult. Finally the threads are highly stressed by the tying needle. Therefore the invention has the further purpose of simplifying and improving the warp end tying machine in this respect so as to achieve higher tying speeds. This is achieved by making the tying hook hollow in any conventional mannerand connecting the same to a suction source. The tying needle and its drive mechanism can thus be eliminated and difficult adjusting operations are not needed. The ends of the threads, after the loop formation, are merely pulled into the tying hook connected to the suction source and are held by suction force'until the knot has been tightened. Also the mechanical stress of the threads is diminished and higher tying speeds are possible.

Further details and advantages of the invention are setforth with reference to the several exemplary embodiments which are illustrated in the drawings, in which:

FIGS. 1-4 are diagrammatic illustrations of a first exemplary embodiment of the new tying machine in four successive operating positions,

FIGS, 5-8 are longitudinal cross-sectional views along the line VIVI of FIG. 9, also in four successive operating positions which correspond to the ones of FIGS. 1-4, l

FIG. 9 is a side view of the first exemplary embodiment,

FIG. 10 is a longitudinal cross-sectional view of a second exemplary embodiment. H I Forreasons of better understanding the drawings,

' only those parts of the tying machine which differ from the known parts are illustrated. The hollow tying hook I has at its front end the jaw 2. Alongside of the tying hook I- there is arranged the cutter 3 and laterally of the tying hook I there is provided the holding device 4; The holding device comprisesa suction tube-and is connected to a schematically illustrated suction source S (FIG. 5). The suction tube 4 is, as particularly shown in FIG. 9, enlarged on its free end to provide jaws oriented transversely to .the plane of the warp thread groupings, so that a V-shaped inlet slot 5 is formed be tween the two diverging ends 4a and 4b.

The suction tube 4 is supported for reciprocable movement relative to the tying hook 1, whereby, as indicated by arrows Aand B, the suction tube is advantageously supported movably. The tying hook is arranged against movement in an axial direction while'rotatable corresponding to the arrow C. The relative movability of suction tube 4 and tying hook I is arranged so that,

, as can be seen particularly in FIGS. 5 to 8, in the for- 'wardmost position of the suction tube 4 the base 50 of the inlet slot is positioned in front of the front end la of the tying hook and in the rearwardmost position Advantageously the hollow tying hook I, which is constructed in a conventional manner, is also connected to the schematically illustrated suction source S (FIG. by which means the tying needle which is usually arranged in the tying hook may be eliminated.

The threads 6 and 7, which are to be tied, assume first the position which is illustrated in dash-dotted lines in FIG. 1. By moving the suction tube 4 forwardly, the threads are moved towards one another by the V- shaped inlet slot 5 and are simultaneously drawn by the suction force to the base 5a of the inlet slot. A not illustrated first cutter cuts off the two threads on the rlght side so that now the thread ends are drawn into the suction tube 4, as shown in FIG. 2. The suction tube 4 then moves rearwardly and assumes the rearwardmost position illustrated in FIGS. 2 and 6. The ends of the threads 6, 7 are in this manner held by the suction force and the two threads are placed over the tying hook 1. Subsequently the tying hook I performs a full rotation which causes the'two threads to be looped around the tying hook by the jaw 2.. This full rotation takes place between the operating positions illustrated in FIGS. 2 and 3 or FIGS. 6 and 7. Thereafter, the suction tube 4 moves forwardly so that the base 5a of the inlet slot 5 lies in front of the front end 1a of the tying hook. This causes the thread loop, which has in the meantime been formed on the tying hook, to slide off therefrom. The cutter 3 now cuts off a portion of the thread ends projecting over the thread loop. This portion is drawn off by the suction tube 4. The thread ends which are still connected to the threads are now drawn into the tying hook by the suction force and are held therein. The knot tensioner moves backwardly, tensions the threads and. pulls the formed thread loop together to form a knot. By a further, not illustrated cutter, the thread ends which lie behind the knob can then be cut off. The

cut-off ends are drawn off by the tying hook I. The tying process is now completed.

While in the illustrated exemplary embodiment the tying hook is arranged stationarily and the suction tube movably, the arrangement can also be reversed.

FIG. illustrates still a further exemplary embodiment in which the tying hook 1 and the suction tube 4' are both arranged stationarily. The construction of the suction tube 4' and of the tying hook 1' corresponds to the above-described exemplary embodiment. However, the base 5a of the inlet slot 5' is herein recessed sufficiently that it lies behind the jaw 2' of the tying hook 1'. Further a reciprocably movable thread delivery mechanism 9 is provided which moves the thread forwardly in front of the front end of the tying hook as soon as a thread loop is formed on the tying hook by rotation of same. Since the remaining operations correspond to the first-described exemplary embodiment, with the reciprocal movement of the suction tube, however, being replaced by that of the thread delivery mechanism 9, the above discussion of FIGS. 1-9 is equally applicable to the exemplary embodiment illustrated in FIG. 10.

The embodiments of the invention in which exclusive property or privlege is claimed are defined as follows:

1. A warp end tying machine for tying threads from two warp thread groupings comprising a tying hook rotatable about its longitudinal axis and a holding device for the two threads which are to be tied, comprising the improvement wherein said tying hook is hollow and the interior thereof is connected to a suction source, air drawn into said hollow tying book by said suction source holding said two threads to be tied until a knot formed by a rotation of said tying hook is tightened whereby said suction source connection to said hollow tying hook assists in the tying of said knot.

2. The improvement according to claim I, wherein said holding device comprises a suction tube and is connected to said suction source.

3. The improvement according to claim 2, wherein the suction tube is enlarged at its free end to define jaws oriented transversely to the plane of the warp thread groupings and that between the two diverging ends a V-shaped inlet slot is formed.

4. The improvement according to claim 3, wherein the suction tube is supported for reciprocal movement relative to the tying hook in such a manner that in the forwardmost position of the suction tube, the base of the inlet slot is positioned in front of the front end of the tying hook and in the rearwardmost position same is positioned behind the jaw of the tying hook.

5. The improvement according to claim 3, wherein the tying hook and suction tube are both supported stationarily, the base of the inlet slot is arranged behind the jaw of the tying hook and a reciprocably movable thread delivery mechanism is provided between said tying hook and the suction tube.

6. The improvement according to claim 2, wherein the suction tube is arranged laterally alongside said tying hook and is supported for reciprocal movement relative to said tying hook in a longitudinal direction parallel to the longitudinal axis thereof. 

1. A warp end tying machine for tying threads from two warp thread groupings comprising a tying hook rotatable about its longitudinal axis and a holding device for the two threads which are to be tied, comprising the improvement wherein said tying hook is hollow and the interior thereof is connected to a suction sourcE, air drawn into said hollow tying hook by said suction source holding said two threads to be tied until a knot formed by a rotation of said tying hook is tightened whereby said suction source connection to said hollow tying hook assists in the tying of said knot.
 2. The improvement according to claim 1, wherein said holding device comprises a suction tube and is connected to said suction source.
 3. The improvement according to claim 2, wherein the suction tube is enlarged at its free end to define jaws oriented transversely to the plane of the warp thread groupings and that between the two diverging ends a V-shaped inlet slot is formed.
 4. The improvement according to claim 3, wherein the suction tube is supported for reciprocal movement relative to the tying hook in such a manner that in the forwardmost position of the suction tube, the base of the inlet slot is positioned in front of the front end of the tying hook and in the rearwardmost position same is positioned behind the jaw of the tying hook.
 5. The improvement according to claim 3, wherein the tying hook and suction tube are both supported stationarily, the base of the inlet slot is arranged behind the jaw of the tying hook and a reciprocably movable thread delivery mechanism is provided between said tying hook and the suction tube.
 6. The improvement according to claim 2, wherein the suction tube is arranged laterally alongside said tying hook and is supported for reciprocal movement relative to said tying hook in a longitudinal direction parallel to the longitudinal axis thereof. 